Quick question: are those walls you're using there "single-sided" square props? I just tried duplicating this in P6, and the reflections seemed to come out correct. I'll post my sample in a few min. I just used the ground plane, and two single-sided square props (resized), with a chrome material on each. It hasn't finished rendering all the way yet, but so far, I don't see the same problems you have there.

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Tools :  3dsmax 2015, Daz Studio 4.6, PoserPro 2012, Blender v2.74

System: Pentium QuadCore i7, under Win 8, GeForce GTX 780 / 2GB GPU.